JP3379130B2 - Parallel converter for cycloconverter - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a parallel operation device for operating a plurality of cycloconverter devices, which are variable voltage variable frequency power supply devices, in parallel, and in particular, stably controls reactive power generated by a circulating current control type cycloconverter. The present invention relates to a parallel operation device that can perform.

[0002]

2. Description of the Related Art FIG. 88 shows a conventional system configuration when a plurality of cycloconverters for compensating reactive power by controlling the circulating current of a circulating current control type cycloconverter are operated in parallel. FIG. 88 shows, for example, Japanese Patent Laid-Open No. 61-157.
It is a block diagram of the parallel operation apparatus of the conventional cycloconverter apparatus shown by the 266 publication. In the figure, 1, 2, 3
Fig. 89 shows the circuit configuration in detail. Each is an AC power supply BUS.
In the circulating current control type cycloconverter connected in parallel to the load current control circuit, load current control circuits IlC _{1 to} IlC _n for controlling the load current supplied to the load, and circulating current control circuits I ₀ C _{1 to} I ₀ C _n for controlling the circulating current. , And the phase control circuits PHC _{1 to} PHC _n that control the firing phase by receiving control signals from the load current control circuit and the circulating current control circuit.

Reference numerals 4, 5 and 6 are AC electric motors serving as loads of these cycloconverters 1, 2 and 3, 7, 8 and 9 are input transformers for the cycloconverters 1, 2 and 3, and 10 is for power factor improvement. A phase-advancing capacitor, 15 is a voltage transformer for detecting the voltage at the power receiving end of the AC power supply BUS, 16 is a current transformer for measuring the current at the power receiving end of the AC power supply BUS, and 92 is a current transformer for this voltage measuring device 16 , And a reactive power detection circuit for detecting the reactive power of the entire AC power supply BUS receiving end from the current and voltage detected by the instrument transformer 15, 93 controls the reactive power detected by the reactive power detection circuit to a predetermined value. In the total reactive power control circuit for performing the above, a circulating current command value for causing a predetermined circulating current to flow through each cycloconverter 1, 2, 3 is given to each circulating current control circuit I ₀ C _{1 to} I ₀ C _n . Reference numeral 94 is a conventional cycloconverter parallel operation device including these devices.

FIG. 89 is a detailed configuration diagram of the input transformer 7, the cycloconverter 1, and the AC motor 4 of FIG. 88. TR1U, TR1V, and TR1W are power source transformers, C, which constitute the input transformer 7. / C1U, C / C1V, C / C1
W is a U-phase, V-phase and W-phase circulating current type cycloconverter, and U, V and W are armature windings of each phase of the AC motor 4. Circulating current type cycloconverter C / C1U, C /
C1V and C / C1W are positive group converters 95, 97 and 99, negative group converters 96, 98 and 100, and a reactor with an intermediate tap.
It is composed of 101, 102, 103, 104, 105 and 106. In addition, the load current detectors 109, 11 for detecting the load current
2, 115, output current detectors 107, 110, 113 for detecting output currents of the positive group converters 95, 97, 99, negative group converter
Output current detector 108 for detecting 96, 98, 100 output current
, 111, 114 are provided, and these detection signals are fed back to the load current control circuit IlC ₁ and the circulating current control circuit I ₀ C ₁ in FIG. 349 as the measured load current value and the measured circulating current value.

First, the load current control operation of the circulating current type cycloconverter will be described by taking the U phase as an example. The detected value of the load current Iu detected by the load current detector 109 is a deviation ε2 from the load current command Iu * in the load current control circuit IlC _1.
= Iu * -Iu is obtained, and the phase control circuit PHC ₁ is controlled so that the cycloconverter C / C1U generates a voltage proportional to this. On the other hand, in order to control the circulating current, the output current of the positive group converter 95 detected by the output current detector 107 and the output current of the negative group converter 96 detected by the output current detector 108 are compared. I _0u
To detect as. The circulating current I _0u is the circulating current control circuit I _0.
At C _1, it is compared with the command value I _0u *, the deviation ε3 is obtained, and the output voltage Vp of the positive group converter 95 and the output voltage Vn of the negative group converter 96 are unbalanced by an amount proportional to the deviation. And controls the phase control circuit PHC ₁ . The differential voltage between Vp and Vn is applied to the DC reactors 101 and 102, and the circulating current I _0u flows. If the circulating current I _0u flows more than the command value I _0u *, the deviation ε3 becomes negative, and Vp <Vn, and I _0u is reduced, so that the circulating current I _0u is equal to the command value I _0u *. Controlled to be. V phase, W
The phases are similarly controlled, and normally the circulating current command value I _0u
*, I _{0 v} *, it gives the I _0w * at the same value, well without necessarily the same, there is a method of changing.

Next, the control operation of the reactive power at the power receiving end of the conventional cycloconverter parallel operation device 94 will be described. FIG. 90 is a block diagram showing detailed blocks of the integrated reactive power control circuit 93 of the cycloconverter parallel operation device 94. In the figure, 116 is a comparator for comparing the command value Qt * of the total reactive power at the power receiving end with the reactive power detection value Qt and deriving the deviation between them, 117 is a control compensation circuit, 118-121 are operational amplifiers, 122 ~ 125 is a limiter, and 126 to 129 are adders.

That is, in the comparator 116, the total reactive power command value Q
The reactive power Qt to be compared with t * is introduced into the reactive power calculating circuit 92 by the voltage at the receiving end and the current detected by the transformer 15 for the instrument and the current transformer 16 for the instrument, and the phase of the voltage is only 90 °. It is obtained by multiplying that value by the current and adding three phases.
The comparator 116 obtains the deviation ε1 = Qt * −Qt between the total reactive power command value Qt * and the reactive power Qt, and the control compensation circuit
Output to 117. The control compensation circuit 117 proportionally or integrally amplifies the deviation signal input from the comparator 116, and outputs a circulating current command I ₀ * for all the cycloconverters 1 to 3. This circulating current command I ₀ * is applied to each cycloconverter 1
The following processes are performed in order to distribute in proportion to the output capacities of 3 to 3, and to maintain the characteristics of the circulating current type cycloconverter without interrupting the circulating current.

That is, the operational amplifiers 118 to 121 are amplifiers having a distribution system multiple proportional to the capacities of the corresponding cycloconverters. If all the cycloconverter capacities are the same, their gains are G1 = G2 = G3. = …… = G
n = 1. Further, if only the capacity of the cycloconverter 2 is small and is 1/10 of that of the other cycloconverters, G2 = 0.1, G1 = G3 = ... = Gn = 1. The circulating current command value I ₀₁ * of the cycloconverter 1 is given by the output signal of the operational amplifier 118 via the limiter circuit 122 and the adder 126. The limiter circuit 122 is shown in FIG.
When the input signal ei is positive, the output signal eo is output as it is, and when the input signal ei is negative, the output signal eo is limited to zero and eo = 0 is output. That is, the circulating current command I ₀₁ * is always limited to a positive value.

Further, the output eo of the limiter circuit 122 is the minimum circulating current command ΔI set separately by the adder 126.
₀ * is added to obtain the circulating current command I ₀₁ *. Therefore,
The circulating current command I ₀₁ * takes the following values. I ₀₁ * = eo + ΔI ₀ * Circulation current command I ₀₂ *, I of other cycloconverter
_The same applies to ₀₃ *, ... I _0n *.

When the detected value of the reactive power at the power receiving end (the delay is positive) Qt is smaller than the command value Qt *, the deviation ε
1 = Qt * -Qt becomes a positive value, and the output I ₀ * of the control compensation circuit 117 is increased. Therefore, the circulating current command value I ₀₂ *, I ₀₃ *, ..., I _0n * given to each cycloconverter also increases to increase the actual circulating current. If the circulating current of the cycloconverter increases, the delayed reactive power Qt at the power receiving end increases although it is non-linear, and finally Qt = Qt *.

On the contrary, when Qt * <Qt, the deviation ε
1 becomes a negative value, and the circulating current of each cycloconverter is reduced to reduce Qt, and as a result, Qt = Qt * is controlled. When the deviation ε1 has a large negative value, the output I ₀ * of the control compensation circuit 117 has a negative value. However, the output eo of the limiter circuits 122 to 125 does not become negative, and eo = 0. Therefore, the circulating current command value of each cycloconverter becomes I ₀₁ * = I ₀₂ * = I ₀₃ * = ... = I _0n * = ΔI ₀ *, and the minimum circulating current continues to flow. That is, since the circulating current is not interrupted, the characteristics of the circulating current type cycloconverter can be maintained.

[0012]

Since the conventional parallel converter of the cycloconverter is configured as described above, the total reactive power at the power receiving end is determined by the deviation from the command value of the total reactive power of each cycloconverter. The circulating current command is created directly. However, while the reactive power generated by each cycloconverter is the total value of the reactive power due to the circulating current and the reactive power due to the load current,
The conventional device does not consider the relationship with the load current.
Further, due to the non-linearity between the generated reactive power and the circulating current, there is a problem that the response of the total reactive power control cannot be improved in combination with the above problem.

The present invention has been made to solve the above problems, and an object thereof is to improve the response of the total reactive power control.

[0014]

A cycloconverter parallel operation apparatus according to claim 1 of the present invention is provided with a phase advancing capacitor which is collectively connected to a power receiving end of an AC power source, and detects a total reactive power detector at the power receiving end. When the measured reactive power is delayed reactive power, the delayed reactive power does not generate an output in a predetermined dead zone region, but generates an output in accordance with the dead zone being exceeded,
In the case of advanced reactive power, a limiter circuit that generates an output according to the advanced reactive power, and a calculation control compensation circuit that generates an individual reactive power command according to the output of this limiter circuit,
An individual reactive power control circuit that individually controls the circulating current of the cycloconverter based on the deviation between the reactive power individually generated by the cycloconverter and the individual reactive power command generated by the calculation control compensation circuit is provided. is there.

According to a second aspect of the present invention, there is provided a parallel operation device for a cycloconverter, wherein a batch insertion phase advancing capacitor which is collectively connected to a power receiving end of an AC power source is provided, and individual phase advancing is provided to each of the feeding systems of the circulating current type cycloconverter. If a real reactive power detected by the integrated reactive power detector at the receiving end is a delayed reactive power with a capacitor installed, no output will occur in the specified dead zone region and a corresponding output will be generated if the delayed reactive power exceeds the dead zone. However, in the case of advanced reactive power, a limiter circuit that generates an output according to the advanced reactive power, an operation control compensation circuit that generates an individual reactive power command corresponding to the output of this limiter circuit, a cycloconverter and an individual phase advance. Based on the deviation between the reactive power generated individually by the capacitors and the individual reactive power command generated by the calculation control compensation circuit, the It is provided with a an individual reactive power control circuit for controlling the circulating current of the inverter.

According to a third aspect of the present invention, there is provided a parallel operation device for a cycloconverter, wherein a batch insertion phase advancing capacitor which is collectively connected to a power receiving end of an AC power source is provided, and individual phase advancing is provided for each of the feeding systems of the circulating current type cycloconverter. If a real reactive power detected by the integrated reactive power detector at the receiving end is a delayed reactive power with a capacitor installed, no output will occur in the specified dead zone region and a corresponding output will be generated if the delayed reactive power exceeds the dead zone. In the case of advanced reactive power, a limiter circuit that generates an output according to the advanced reactive power, an operation control compensation circuit that generates an individual reactive power command according to the output of this limiter circuit, and a cycloconverter are generated individually. Based on the deviation between the reactive power and the individual reactive power command generated by the calculation control compensation circuit, the circulating current of the cycloconverter is individually calculated. Gosuru is provided with a an individual reactive power control circuit.

According to the fourth to sixth aspects of the present invention, the cycloconverter parallel operation apparatus is provided with a limiter circuit for limiting the output of the control circuit and / or the individual reactive power control circuit.

[0018]

In the parallel operating device for the cycloconverter according to claim 1 of the present invention, each cycloconverter is provided with an individual generated reactive power control system, and the reactive power command for each cycloconverter is applied to the receiving end. When the measured reactive power detected by the total reactive power detector is delayed reactive power, the delayed reactive power does not generate an output in the predetermined dead zone, but when the dead reactive zone exceeds the dead zone, a corresponding output is generated, and in the case of advanced reactive power , The setting is controlled by the output of the arithmetic control compensation circuit that generates the individual reactive power command according to the output of the limiter circuit that generates the output according to the advanced reactive power.
The total reactive power control can be controlled stably, and the control with a quick response becomes possible.

In the parallel operating device of the cycloconverter according to the second aspect of the present invention, each cycloconverter is provided with an individual generated reactive power control system, and the reactive power command for each cycloconverter is applied to the receiving end. When the measured reactive power detected by the total reactive power detector is delayed reactive power, the delayed reactive power does not generate an output in the predetermined dead zone, but when the dead reactive zone exceeds the dead zone, a corresponding output is generated, and in the case of advanced reactive power , The output of the limiter circuit that generates the output according to the advanced reactive power is generated. The setting control is performed by the output of the calculation control compensation circuit that generates the individual reactive power command according to the output of the limiter circuit. A phase-advancing capacitor is provided, and the reactive power generated individually by the cycloconverter and the individual phase-advancing capacitor and the individual reactive power command Since controlling the circulating currents individually cycloconverter based on the difference, total reactive power control with controllable stable, thereby enabling more rapid control response.

According to a third aspect of the present invention, the cycloconverter parallel operation apparatus is provided with a separate reactive power control system for each cycloconverter, and the reactive power command for each cycloconverter is applied to the receiving end. When the measured reactive power detected by the total reactive power detector is delayed reactive power, the delayed reactive power does not generate an output in the predetermined dead zone, but when the dead reactive zone exceeds the dead zone, a corresponding output is generated, and in the case of advanced reactive power , The output of the limiter circuit that generates the output according to the advanced reactive power is generated. The setting control is performed by the output of the calculation control compensation circuit that generates the individual reactive power command according to the output of the limiter circuit. A phase-advancing capacitor is provided, and individual support is performed based on the deviation between the reactive power generated individually by the cycloconverter and the individual reactive power command. Since controlling the circulating current of the black converter, total reactive power control with controllable stable, thereby enabling more rapid control response.

In the parallel operating device of the cycloconverter according to claims 4 to 6 of the present invention, since the output of the control circuit and / or the individual reactive power control circuit is limited, the circulating current can be limited, and the characteristics of the circulating current type cycloconverter can be limited. Can be ensured and the control response can be improved.

[0022]

EXAMPLES Example 1. Embodiment 1 of the present invention will be described below with reference to the drawings. In FIG. 1, 11, 12, 13, and 14 are switches, 17, 18, and 19 are current transformers for measuring the input current of each cycloconverter 1 to 3, and 20, 21, and 22 are AC power supplies. A circulating current command generation circuit for controlling the total reactive power at the power receiving end of the BUS and the reactive power generated individually for each of the cycloconverters 1 to 3, and 23 is a cycloconverter parallel operation apparatus according to the present invention having the above-described configurations.

A detailed block diagram of the circulating current command generation circuit 20 is shown in FIG. In FIG. 2, 24 is a total reactive power detection circuit that detects the total reactive power from the voltage and current at the receiving end detected by the transformer 15 for the meter and the current transformer 16 for the meter, and 25 is the total reactive power detection circuit. Introduces the measured reactive power to be detected, and in the case of delayed reactive power, no output is generated in the predetermined dead zone region, and output is generated when the dead zone is exceeded, and in the case of advanced reactive power, according to the advanced reactive power. A reference numeral 35 is a calculation control compensating circuit for proportionally amplifying or integral amplifying the deviation detection value Qtf of the total reactive power which is the output of this limiter circuit, and generating a reactive power reference command for each cycloconverter. , 36 is an individual reactive power detection circuit that detects the reactive power generated by each cycloconverter from the voltage and current detected by the instrument transformer 15 and the instrument current transformer 17, and 37 is the arithmetic control Cycloconverter to generate the 償回 passage 35 individual generator reactive power reference Qi
A comparator for comparing * and the individual reactive power detection value Qi detected by the individual reactive power detection circuit 36, and a generated reactive power control circuit 38 for proportionally amplifying or integral amplifying the deviation ε1 output from the comparator 37.

The load current control means and the circulating current control means are controlled in the same manner as in the prior art, but the method of reactive power control at the power receiving end is different and will be described below. As shown in FIG. 1, the cycloconverters 1 to 3 and the input transformer 7 to
The switch 9 is connected to the AC power supply BUS in parallel by switches 12 to 14. Further, as in the case where only the cycloconverter 1 is shown in FIG. 2, each cycloconverter has a detection function and a control function of the total reactive power at the power receiving end. If it becomes abnormal, it does not affect the control of other cycloconverters and total reactive power.

Next, the control system of the total reactive power will be described for the cycloconverter 1 with reference to FIG. The total reactive power detection circuit 24 receives the voltage and current detection signals of the power receiving end from the instrument transformer 15 and the instrument current transformer 16, and detects the total reactive power at the power receiving end. Total reactive power detection circuit
The total reactive power Qt detected by 24 is input to the limiter circuit 25. When the actually measured reactive power detected by the total reactive power detection circuit 24 is delayed reactive power, the limiter circuit 25 determines the total reactive power management value Qt *. No output is generated in the dead zone area, and a negative signal is generated when the dead zone area is exceeded.
In the case of advanced reactive power, a positive signal corresponding to the reactive power is generated. The output Qtf of the limiter circuit 25 is introduced into the operation control compensation circuit 35, and proportional amplification or integral amplification is performed to output a reactive power reference command for each cycloconverter. That is, the individual generated reactive power command Qi * is increased / decreased by the deviation between the control value Qt * of the total reactive power and the detected value Qt of the total reactive power to control the reactive power at the power receiving end. The arithmetic control compensating circuit 35 is given a preset no-load reactive power compensation amount as an initial value.

Next, the individual reactive power detection circuit 36 detects the generated reactive power Qi of the cycloconverter 1 by the voltage and current signals obtained from the instrument transformer 15 and the instrument current transformer 17. The generated reactive power Qi detected by the individual reactive power detection circuit 36 and the control value Qt * of the total reactive power output by the arithmetic control compensation circuit 35 are compared by a comparator 37 with a deviation ε1 =
Qi * -Qi is taken and input to the individually-generated reactive power control circuit 38 formed of a proportional-integral circuit. The individually generated reactive power control circuit 38 is the cycloconverter 1 according to the deviation ε1.
The circulating current command I ₀₁ * is output to the circulating current control circuit I ₀ C1 to control the circulating current of the cycloconverter 1 as in the conventional case.

FIG. 3 is a characteristic diagram showing an example of the operation mode of the apparatus of FIG. In Fig. 3 (a), Qcap is the forward reactive power taken by the phase advancing capacitor 10, Qc / cL is the delayed reactive power taken by the entire cycloconverter, and the circulating current of the cycloconverter 1 is at the minimum value (reactive power). Reactive power (when compensation is not performed), Qi * is the individually generated reactive power command of the cycloconverter 1, and Qc
/ CL is generated to compensate for the amount missing from Qcap. Here, the central portion of Qi * is the portion where the minimum circulating current is flowing to the cycloconverter 1, and Qi * does not fall below this. Also, FIG. 3 (b)
Qt is the reactive power at the receiving end, and the delayed reactive power Qc / cL increases due to an increase in the load current and the circulating current, and the advanced reactive power Qcap taken by the phase advance capacitor 10
It is the waveform of the part that exceeds.

FIG. 3 (c) shows the circulating current command I ₀₁ * and the generated reactive power Qi when the load current Il1 of the cycloconverter 1 changes as shown by the broken line. As is clear from the figure, the circulating current command I ₀₁ * changes according to the individually generated reactive power command Qi *, but the load current Il1 changes as shown by the broken line, so that the generated reactive power Qi of the cycloconverter 1 is changed. Has a waveform obtained by adding Il1 and I ₀₁ * as shown by the alternate long and short dash line. 3D shows the circulating current command I _0n * and the generated reactive power Qi when the load current Iln of the cycloconverter 3 changes as shown by the broken line. As is clear from the figure, the circulating current command I _0n * changes according to the individually generated reactive power command Qi *, but since the load current Iln changes as shown by the broken line, the generated reactive power Qi of the cycloconverter 1 is changed. Has a waveform obtained by adding Il1 and I ₀₁ * as shown by the alternate long and short dash line.

That is, when Qc / cL <Qcap, by increasing the circulating current of each cycloconverter,
It can be set to Qtf = 0. On the other hand, Qc / cL> Q
In the case of cap, Qtf = 0 can be set by reducing the circulating current of each cycloconverter.

FIG. 4 is a block diagram showing a first modification of the first embodiment. In FIG. 4, 39 is an upper limiter circuit that limits the output of the arithmetic control compensation circuit 35. The upper limit limiter circuit 39 can reliably limit the upper limit of the individually generated reactive power command generated by the calculation control compensation circuit 35. Therefore, the maximum reactive power compensation amount of the cycloconverter 1 can be limited, and the circulating current can be limited. Therefore, it is not necessary to increase the capacity of the cycloconverter 1 with respect to the capacity of the load more than necessary. it can.

FIG. 5 shows an example of operation modes of the parallel operation device for the cycloconverter shown in FIG. In FIG.
The same reference numerals as those in FIG. 3 indicate the same signals. The individually generated reactive power command Qi * in FIG. 5 (a) initially exceeds the limit value of the upper limit limiter circuit 39, but the circulating current command I ₀₁ shown in FIG. 5 (c).
It is restricted like *.

FIG. 6 is a block diagram showing a second modification of the first embodiment. In FIG. 6, reference numeral 42 denotes a lower limiter circuit that limits the output of the arithmetic control compensation circuit 35. The lower limit limiter circuit 42 can reliably limit the lower limit of the individually generated reactive power command generated by the calculation control compensation circuit 35. Therefore, since the minimum individually generated reactive power command by the cycloconverter 1 can be secured, the circulating current can be regulated so as not to be interrupted, and the characteristics of the circulating current type cycloconverter can be reliably secured.

FIG. 7 shows an example of operation modes of the parallel operation device for the cycloconverter shown in FIG. In FIG.
The same reference numerals as those in FIG. 3 indicate the same signals. In FIG. 7 (d), it can be seen that the load current Iln becomes the minimum and the generated reactive power also decreases, but the lower limit limiter circuit 42 surely secures the lower limit value of the generated reactive power.

FIG. 8 is a block diagram showing a third modification of the first embodiment. In FIG. 8, reference numeral 45 is an upper / lower limit limiter circuit for limiting the output of 35. The upper and lower limit limiter circuit 45 can reliably limit the upper and lower limits of the individually generated reactive power command generated by the calculation control compensation circuit 35. Therefore, the maximum reactive power compensation amount of the cycloconverter 1 can be limited, and the circulating current can be limited. Therefore, it is not necessary to increase the capacity of the cycloconverter 1 with respect to the capacity of the load more than necessary. it can. Further, since the minimum individually generated reactive power command by the cycloconverter 1 can be secured, the circulating current can be regulated so as not to be interrupted, and the characteristics of the circulating current type cycloconverter can be reliably secured. further,
Since the control range of the individually generated reactive power is defined, the control response, that is, the control output response of the individually generated reactive power command Qi * can be increased.

FIG. 9 shows an example of operation modes of the parallel operation device for the cycloconverter shown in FIG. In FIG.
The same reference numerals as those in FIG. 3 indicate the same signals.

FIG. 10 is a block diagram showing a modified example 4 of the first embodiment. In FIG. 10, 48 is an individual reactive power control circuit
This is a lower limiter circuit that limits the output of 38. The lower limit limiter circuit 48 can reliably limit the lower limit of the circulating current command generated by the individual reactive power control circuit 38. Therefore, the minimum circulating current command can be specified so that the circulating current of the cycloconverter 1 is not interrupted, and the characteristics of the circulating current type cycloconverter can be reliably ensured.

FIG. 11 shows an example of the operation modes of the parallel operation device for the cycloconverter shown in FIG. In FIG.
The same reference numerals as those in FIG. 3 indicate the same signals. As shown in FIGS. 11 (c) and 11 (d), the circulating current commands I ₀₁ * and I _0n * can be reliably limited to the lower limit of the minimum circulating current command.

FIG. 12 is a block diagram showing a modified example 5 of the first embodiment. In FIG. 12, 51 is an individual reactive power control circuit
It is an upper limiter circuit that limits the output of 38. The upper limit limiter circuit 51 can reliably limit the lower limit of the circulating current command generated by the individual reactive power control circuit 38. Therefore, the upper limit of the circulating current command of the cycloconverter 1 can be limited, so that the capacity of the cycloconverter 1 does not have to be made larger than necessary to the capacity of the load, and an inexpensive device can be obtained.

FIG. 13 shows an example of operation modes of the parallel operation device for the cycloconverter shown in FIG. In FIG.
The same reference numerals as those in FIG. 3 indicate the same signals. As shown in FIGS. 13 (c) and 13 (d), the circulating current commands I ₀₁ *, I _0n * can be reliably limited to the upper limit of the maximum circulating current command.

FIG. 14 is a block diagram showing a modified example 6 of the first embodiment. In FIG. 14, 54 is an individual reactive power control circuit
An upper and lower limiter circuit that limits the output of 38. The upper and lower limit limiter circuit 54 can reliably limit the upper and lower limits of the circulating current command generated by the individual reactive power control circuit 38. Therefore, the minimum circulating current command can be specified so that the circulating current of the cycloconverter 1 is not interrupted, and the characteristics of the circulating current type cycloconverter can be reliably ensured. Further, since the upper limit of the circulating current command of the cycloconverter 1 can be limited, the capacity of the cycloconverter 1 does not have to be made larger than necessary to the capacity of the load, so that an inexpensive device can be obtained. Further, since the control range of the circulating current is limited, the influence on the fluctuation of the load current can be suppressed.

FIG. 15 shows an example of the operation modes of the parallel operation device for the cycloconverter shown in FIG. In FIG.
The same reference numerals as those in FIG. 3 indicate the same signals. As shown in FIGS. 15 (c) and 15 (d), the circulating current commands I ₀₁ *, I _0n * can be reliably limited to the lower limit of the minimum circulating current command and the upper limit of the maximum circulating current command.

FIG. 16 is a block diagram showing a modified example 7 of the first embodiment. In FIG. 16, 57 is an upper limiter circuit that limits the output of the arithmetic control compensation circuit 35. The upper limit limiter circuit 57 can reliably limit the upper limit of the individually generated reactive power command generated by the calculation control compensation circuit 35. Also, 58
Is a lower limiter circuit that limits the output of the individual reactive power control circuit 38. The lower limit limiter circuit 58 can reliably limit the lower limit of the circulating current command generated by the individual reactive power control circuit 38. Therefore, the maximum reactive power compensation amount of the cycloconverter 1 can be limited, and the circulating current can be limited. Therefore, it is not necessary to increase the capacity of the cycloconverter 1 with respect to the capacity of the load more than necessary. it can. Further, the minimum circulating current command can be specified so that the circulating current of the cycloconverter 1 is not interrupted, and the characteristics of the circulating current type cycloconverter can be reliably ensured.

FIG. 17 shows an example of operation modes of the parallel operation device for the cycloconverter shown in FIG. In FIG. 17,
The same reference numerals as those in FIG. 3 indicate the same signals. As shown in FIGS. 17 (c) and (d), the circulating current commands I ₀₁ *, I _0n * can be reliably limited to the lower limit of the minimum circulating current command, and the maximum reactive power compensation amount maxΔQ can be limited. Circulating current is limited.

FIG. 18 is a block diagram showing a modified example 8 of the first embodiment. In FIG. 18, a diode 61 is used for the output of the individual reactive power control circuit 38 to surely limit the lower limit of the circulating current command value and secure the characteristics of the circulating current type cycloconverter. or circuit configuration, circulating current specified value setter 62
Is provided. Therefore, even if the individual reactive power control circuit 38 outputs a negative signal, the minimum circulating current can be controlled and secured, and the circulating current is not interrupted, so that the characteristics of the circulating current type cycloconverter can be reliably secured.

FIG. 19 shows an example of operation modes of the parallel operation device for the cycloconverter shown in FIG. In FIG.
The same reference numerals as those in FIG. 3 indicate the same signals. As shown in FIG. 19 (c), the circulating current command I ₀₁ * can be reliably limited to the minimum circulating current command I _0b specified by the circulating current specified value setter.

FIG. 20 is a block diagram showing a modified example 9 of the first embodiment. FIG. 20 shows that when the output of the individual reactive power control circuit 38 is positive, it is output as it is, and when it is negative, it is zero output in order to reliably limit the lower limit of the circulating current command value and ensure the characteristics of the circulating current type cycloconverter. A lower limit limiter circuit 65 is added, and the output I ₀₁ ** is added to the output I _0b of the circulating current specified value setter 66 by an adder 67 to obtain a circulating current command. Therefore, at least the circulating current set by circulating current specified value setter 66 flows, so that the characteristics of the circulating current type cycloconverter can be reliably ensured.

FIG. 21 shows an example of the operation modes of the parallel operation device for the cycloconverter shown in FIG. In FIG. 21,
The same reference numerals as those in FIG. 3 indicate the same signals. As shown in FIG. 21 (c), the circulating current command I ₀₁ * of the individual reactive power control circuit 38 is limited to a positive signal, and the circulating current command is equal to or more than the output I _0b of the circulating current specified value setter 66. The value can be secured.

FIG. 22 is a block diagram showing a tenth modification of the first embodiment. FIG. 22 shows that an upper limiter circuit 70 is added to the output of the arithmetic control compensation circuit 35 for individual reactive power command in order to reliably limit the upper limit of the individual reactive power compensation amount, and the lower limit of the circulating current command value is ensured. A diode 71 is used for the output of the individual reactive power control circuit 38 in order to secure the characteristics of the limiting and circulating current type cycloconverter. or circuit configuration,
A circulating current specified value setter 72 is added. Therefore, the maximum reactive power compensation amount can be limited, and the circulating current can be limited. Therefore, it is not necessary to increase the capacity of the cycloconverter to the capacity of the load more than necessary, so that inexpensive equipment can be provided. Further, since the minimum circulating current can be controlled and secured, the circulating current is not interrupted, and the characteristics as the circulating current type cycloconverter can be secured.

FIG. 23 shows an example of the operation modes of the parallel operation device for the cycloconverter shown in FIG. In FIG. 23,
The same reference numerals as those in FIG. 3 indicate the same signals.

FIG. 24 is a block diagram showing a modified example 11 of the first embodiment. FIG. 24 shows that an upper limiter circuit 75 is added to the output of the calculation control compensation circuit 35 for individual reactive power command in order to reliably limit the upper limit of the individual reactive power compensation amount, and the lower limit of the circulating current command value is ensured. In order to secure the characteristics of the circulating current type cycloconverter by limiting to, the output of the individual reactive power control circuit 38 is output as it is when the output is positive, and a lower limit limiter circuit 76 that makes zero output when it is negative is added. Output I ₀₁ **
Further, the output I _0b of the circulating current specified value setting unit 77 is added by the adder 78 to _obtain the circulating current command. Therefore, the maximum reactive power compensation amount can be limited, and the circulating current can be limited. Therefore, it is not necessary to increase the capacity of the cycloconverter to the capacity of the load more than necessary, so that inexpensive equipment can be provided. Further, since the minimum circulating current can be controlled and secured, the circulating current is not interrupted, and the characteristics as the circulating current type cycloconverter can be secured.

FIG. 25 shows an example of the operation modes of the parallel operation device for the cycloconverter shown in FIG. In FIG. 25,
The same reference numerals as those in FIG. 3 indicate the same signals.

FIG. 26 is a block diagram showing a modified example 12 of the first embodiment. FIG. 26 shows that in order to reliably limit the upper limit of the individual reactive power compensation amount and to reliably specify the lower limit of the circulating current command value, and to limit the control range of the individual reactive power command and speed up the response, An upper and lower limit limiter circuit 81 is added to the output of the arithmetic control compensation circuit 35, and the output of the individual reactive power control circuit 38 is added to ensure the characteristics of the circulating current type cycloconverter by securely limiting the lower limit of the circulating current command value. Using diode 82, max. or circuit configuration, and a circulating current specified value setter 83 is added.

FIG. 27 shows an example of the operation modes of the parallel operation device for the cycloconverter shown in FIG. In FIG. 27,
The same reference numerals as those in FIG. 3 indicate the same signals.

FIG. 28 is a block diagram showing a modified example 13 of the first embodiment. FIG. 28 shows that in order to reliably limit the upper limit of the individual reactive power compensation amount, to reliably specify the lower limit of the circulating current command value, and to limit the control range of the individual reactive power command and speed up the control response. An upper / lower limit limiter circuit 86 is added to the output of the calculation control compensation circuit 35 for the individual reactive power command, and the lower limit of the circulating current command value is surely limited to ensure the characteristics of the circulating current type cycloconverter. The lower limit of the lower limit limiter circuit 86 is set to zero, and the individual reactive power control circuit 38 can be output. When it is positive, it is output as it is, and when it is negative, a lower limit limiter circuit 87 is added, and its output I ₀₁ ** is added. The output I _0b of the circulating current specified value setter 88 is added by an adder 89 to give a circulating current command.

FIG. 29 shows an example of the operation modes of the parallel operation device for the cycloconverter shown in FIG. In FIG. 29,
The same reference numerals as those in FIG. 3 indicate the same signals.

Example 2. Embodiment 2 of the present invention will be described below with reference to the drawings. In FIG. 30, 10a, 10b, and 10c are individual phase-advancing capacitors for compensating for the minimum delay reactive power generated by each cycloconverter 1 to 3, 11, 12, 13, and 14, respectively.
Is a switch, 17, 18 and 19 are cycloconverters 1 to 3,
And phase-advancing capacitors 10a to 10c Current transformers for measuring instruments for detecting individual input currents, 20, 21, 22 are total reactive power at the receiving end of the AC power supply BUS and each cycloconverter 1
˜3 Circulating current command generation circuit for controlling individual generated reactive power, and 23 is a cycloconverter parallel operation apparatus according to the present invention having the above-mentioned configurations.

FIG. 31 shows a detailed block diagram of the circulating current command generation circuit 20. In FIG. 31, 24 is an instrument transformer 15, and a receiving end voltage detected by the instrument current transformer 16, and a total reactive power detection circuit for detecting total reactive power from the current, and 25 is a total reactive power detection circuit. Introduces the measured reactive power to be detected, and in the case of delayed reactive power, no output is generated in the predetermined dead zone region, and output is generated when the dead zone is exceeded, and in the case of advanced reactive power, according to the advanced reactive power. A reference numeral 35 is a calculation control compensating circuit for proportionally amplifying or integral amplifying the deviation detection value Qtf of the total reactive power which is the output of this limiter circuit, and generating a reactive power reference command for each cycloconverter. , 36 is an individual reactive power detection circuit that detects the reactive power generated by each cycloconverter from the voltage and current detected by the instrument transformer 15 and the instrument current transformer 17, and 37 is the arithmetic control Cycloconverter to generate the 償回 passage 35 individual generator reactive power reference Qi
A comparator for comparing * and the individual reactive power detection value Qi detected by the individual reactive power detection circuit 36, and a generated reactive power control circuit 38 for proportionally amplifying or integral amplifying the deviation ε1 output from the comparator 37.

The load current control means and the circulating current control means are controlled in the same manner as in the prior art, but the method of reactive power control at the power receiving end is different, and will be described below. As shown in FIG. 30, each cycloconverter 1 to 3 and input transformer 7 to
The switch 9 is connected to the AC power supply BUS in parallel by switches 12 to 14. Further, as in the case where only the cycloconverter 1 is shown in FIG. 31, each cycloconverter has a detection function and a control function of the total reactive power at the power receiving end. If it becomes abnormal, it does not affect the control of other cycloconverters and total reactive power.

Next, the control system of the total reactive power will be described for the cycloconverter 1 with reference to FIG. The total reactive power detection circuit 24 receives the voltage and current detection signals of the power receiving end from the instrument transformer 15 and the instrument current transformer 16, and detects the total reactive power at the power receiving end. Total reactive power detection circuit
The total reactive power Qt detected by 24 is input to the limiter circuit 25. When the actually measured reactive power detected by the total reactive power detection circuit 24 is delayed reactive power, the limiter circuit 25 determines the total reactive current according to the management value Qt *. No output is generated in the dead zone area, and a negative signal is generated when the dead zone area is exceeded.
In the case of advanced reactive power, a positive signal corresponding to the reactive power is generated. The output Qtf of the limiter circuit 25 is introduced into the operation control compensation circuit 35, and proportional amplification or integral amplification is performed to output a reactive power reference command for each cycloconverter. That is, the individual generated reactive power command Qi * is increased / decreased by the deviation between the control value Qt * of the total reactive power and the detected value Qt of the total reactive power to control the reactive power at the power receiving end. The arithmetic control compensating circuit 35 is given a preset no-load reactive power compensation amount as an initial value.

Next, the individual reactive power detection circuit 36 detects the reactive power Qi generated by the cycloconverter 1 based on the voltage and current signals obtained from the instrument transformer 15 and the instrument current transformer 17. The generated reactive power Qi detected by the individual reactive power detection circuit 36 and the control value Qt * of the total reactive power output by the arithmetic control compensation circuit 35 are compared by a comparator 37 with a deviation ε1 =
Qi * -Qi is taken and input to the individually-generated reactive power control circuit 38 formed of a proportional-integral circuit. The individually generated reactive power control circuit 38 is the cycloconverter 1 according to the deviation ε1.
The circulating current command I ₀₁ * is output to the circulating current control circuit I ₀ C1 to control the circulating current of the cycloconverter 1 as in the conventional case. The generated reactive power Qi detected by the individual reactive power detection circuit 36 is reduced in fluctuation because the minimum delayed reactive power generated by the cycloconverter 1 is canceled by the individual phase advance capacitor 10a. Therefore, it is possible to improve the response of the individually generated reactive power control circuit 38.

FIG. 32 is a characteristic diagram showing an example of the operation mode of the apparatus of FIG. In Fig. 32 (a), Qcap is the advanced reactive power that the phase advancing capacitor 10 takes, and Qc / cL is the delayed reactive power that the entire cycloconverter takes. When the circulating current of the cycloconverter 1 is the minimum value (reactive power Reactive power (when compensation is not performed), Qi * is the individually generated reactive power command of the cycloconverter 1, and Qc
/ CL is generated to compensate for the amount missing from Qcap. Here, the central portion of Qi * is the portion where the minimum circulating current is flowing to the cycloconverter 1, and Qi * does not fall below this. Also, FIG. 32 (b)
Qtf is the reactive power at the receiving end, and the delayed reactive power Qc / cL increases due to an increase in the load current and the circulating current, and the advanced reactive power Qca taken by the phase advance capacitor 10 is
The waveform is the part that exceeds p.

FIG. 32 (c) shows the circulating current command I ₀₁ * and the generated reactive power Qi when the load current Il1 of the cycloconverter 1 changes as shown by the broken line. As is clear from the figure, the circulating current command I ₀₁ * changes according to the individually generated reactive power command Qi *, but the load current Il1 changes as shown by the broken line, so that the generated reactive power Qi of the cycloconverter 1 is changed. Has a waveform obtained by adding Il1 and I ₀₁ * as shown by the alternate long and short dash line. FIG. 32 (d) shows the circulating current command I _0n * and the generated reactive power Qi when the load current Iln of the cycloconverter 3 changes as shown by the broken line. As is clear from the figure, the circulating current command I _0n * changes according to the individually generated reactive power command Qi *, but since the load current Iln changes as shown by the broken line, the generated reactive power Qi of the cycloconverter 1 is changed. Has a waveform obtained by adding Il1 and I ₀₁ * as shown by the alternate long and short dash line.

That is, when Qc / cL <Qcap, by increasing the circulating current of each cycloconverter,
It can be set to Qtf = 0. On the other hand, Qc / cL> Q
In the case of cap, Qtf = 0 can be set by reducing the circulating current of each cycloconverter.

FIG. 33 is a block diagram showing a first modification of the second embodiment. In FIG. 33, 39 is an upper limiter circuit that limits the output of the arithmetic control compensation circuit 35. The upper limit limiter circuit 39 can reliably limit the upper limit of the individually generated reactive power command generated by the calculation control compensation circuit 35. Therefore, the maximum reactive power compensation amount of the cycloconverter 1 can be limited, and the circulating current can be limited. Therefore, it is not necessary to increase the capacity of the cycloconverter 1 with respect to the capacity of the load more than necessary. it can.

FIG. 34 shows an example of the operation modes of the parallel operation device for the cycloconverter shown in FIG. In FIG. 34,
The same reference numerals as those in FIG. 32 indicate the same signals. The individually generated reactive power command Qi * in FIG. 34 (a) initially exceeds the limit value of the upper limit limiter circuit 39, but the circulating current command I ₀₁ shown in FIG. 34 (c).
It is restricted like *.

FIG. 35 is a block diagram showing a second modification of the second embodiment. In FIG. 35, reference numeral 42 denotes a lower limiter circuit that limits the output of the arithmetic control compensation circuit 35. The lower limit limiter circuit 42 can reliably limit the lower limit of the individually generated reactive power command generated by the calculation control compensation circuit 35. Therefore, since the minimum individually generated reactive power command by the cycloconverter 1 can be secured, the circulating current can be regulated so as not to be interrupted, and the characteristics of the circulating current type cycloconverter can be reliably secured.

FIG. 36 shows an example of operation modes of the parallel operation device for the cycloconverter shown in FIG. In FIG. 36,
The same reference numerals as those in FIG. 32 indicate the same signals. In FIG. 36 (d), although the load current Iln becomes the minimum and the generated reactive power also decreases, it is understood that the lower limit limiter circuit 42 surely secures the lower limit value of the generated reactive power.

FIG. 37 is a block diagram showing a third modification of the second embodiment. In FIG. 37, reference numeral 45 is an upper and lower limiter circuit that limits the output of the arithmetic control compensation circuit 35. The upper and lower limit limiter circuit 45 can reliably limit the upper and lower limits of the individually generated reactive power command generated by the calculation control compensation circuit 35. Therefore, the maximum reactive power compensation amount of the cycloconverter 1 can be limited, and the circulating current can be limited. Therefore, it is not necessary to increase the capacity of the cycloconverter 1 with respect to the capacity of the load more than necessary. it can. Further, since the minimum individually generated reactive power command by the cycloconverter 1 can be secured, the circulating current can be regulated so as not to be interrupted, and the characteristics of the circulating current type cycloconverter can be reliably secured. Furthermore, since the control range of the individually generated reactive power is specified, the control response, that is, the individually generated reactive power command Q
The control output response of i * can be improved.

FIG. 38 shows an example of operation modes of the parallel operation device for the cycloconverter shown in FIG. In FIG. 38,
The same reference numerals as those in FIG. 32 indicate the same signals.

FIG. 39 is a block diagram showing a modified example 4 of the second embodiment. In FIG. 39, 48 is an individual reactive power control circuit
This is a lower limiter circuit that limits the output of 38. The lower limit limiter circuit 48 can reliably limit the lower limit of the circulating current command generated by the individual reactive power control circuit 38. Therefore, the minimum circulating current command can be specified so that the circulating current of the cycloconverter 1 is not interrupted, and the characteristics of the circulating current type cycloconverter can be reliably ensured.

FIG. 40 shows an example of the operation modes of the parallel operation device for the cycloconverter shown in FIG. In FIG. 40,
The same reference numerals as those in FIG. 32 indicate the same signals. As shown in FIGS. 40 (c) and 40 (d), the circulating current commands I ₀₁ *, I _0n * can be reliably limited to the lower limit of the minimum circulating current command.

FIG. 41 is a block diagram showing a modified example 5 of the second embodiment. In FIG. 41, 51 is an individual reactive power control circuit
It is an upper limiter circuit that limits the output of 38. The upper limit limiter circuit 51 can reliably limit the lower limit of the circulating current command generated by the individual reactive power control circuit 38. Therefore, the upper limit of the circulating current command of the cycloconverter 1 can be limited, so that the capacity of the cycloconverter 1 does not have to be made larger than necessary to the capacity of the load, and an inexpensive device can be obtained.

FIG. 42 shows an example of the operation modes of the parallel operation device for the cycloconverter shown in FIG. In FIG. 42,
The same reference numerals as those in FIG. 32 indicate the same signals. As shown in FIGS. 42 (c) and 42 (d), the circulating current commands I ₀₁ *, I _0n * can be reliably limited to the upper limit of the maximum circulating current command.

FIG. 43 is a block diagram showing a modified example 6 of the second embodiment. In FIG. 43, 54 is an individual reactive power control circuit
An upper and lower limiter circuit that limits the output of 38. The upper and lower limit limiter circuit 54 can reliably limit the upper and lower limits of the circulating current command generated by the individual reactive power control circuit 38. Therefore, the minimum circulating current command can be specified so that the circulating current of the cycloconverter 1 is not interrupted, and the characteristics of the circulating current type cycloconverter can be reliably ensured. Further, since the upper limit of the circulating current command of the cycloconverter 1 can be limited, the capacity of the cycloconverter 1 does not have to be made larger than necessary to the capacity of the load, so that an inexpensive device can be obtained. Further, since the control range of the circulating current is limited, the influence on the fluctuation of the load current can be suppressed.

FIG. 44 shows an example of the operation modes of the parallel operation device for the cycloconverter shown in FIG. In FIG. 44,
The same reference numerals as those in FIG. 32 indicate the same signals. As shown in FIGS. 44 (c) and 44 (d), the circulating current commands I ₀₁ * and I _0n * can be reliably limited to the lower limit of the minimum circulating current command and the upper limit of the maximum circulating current command.

FIG. 45 is a block diagram showing a modified example 7 of the second embodiment. In FIG. 45, 57 is an upper limiter circuit that limits the output of the arithmetic control compensation circuit 35. The upper limit limiter circuit 57 can reliably limit the upper limit of the individually generated reactive power command generated by the calculation control compensation circuit 35. Also, 58
Is a lower limiter circuit that limits the output of the individual reactive power control circuit 38. The lower limit limiter circuit 58 can reliably limit the lower limit of the circulating current command generated by the individual reactive power control circuit 38. Therefore, the maximum reactive power compensation amount of the cycloconverter 1 can be limited, and the circulating current can be limited. Therefore, it is not necessary to increase the capacity of the cycloconverter 1 with respect to the capacity of the load more than necessary. it can. Further, the minimum circulating current command can be specified so that the circulating current of the cycloconverter 1 is not interrupted, and the characteristics of the circulating current type cycloconverter can be reliably ensured.

FIG. 46 shows an example of operation modes of the parallel operation device for the cycloconverter shown in FIG. In FIG. 46,
The same reference numerals as those in FIG. 32 indicate the same signals. As shown in FIGS. 46 (c) and (d), the circulating current commands I ₀₁ *, I _0n * can be reliably limited to the lower limit of the minimum circulating current command, and the maximum reactive power compensation amount maxΔQ can be limited. Circulating current is limited.

FIG. 47 is a block diagram showing a modified example 8 of the second embodiment. In FIG. 47, a diode 61 is used for the output of the individual reactive power control circuit 38 in order to reliably limit the lower limit of the circulating current command value and ensure the characteristics of the circulating current type cycloconverter. or circuit configuration, circulating current specified value setter 62
Is provided. Therefore, even if the individual reactive power control circuit 38 outputs a negative signal, the minimum circulating current can be controlled and secured, and the circulating current is not interrupted, so that the characteristics of the circulating current type cycloconverter can be reliably secured.

FIG. 48 shows an example of the operation modes of the parallel operation device for the cycloconverter shown in FIG. In FIG. 48,
The same reference numerals as those in FIG. 32 indicate the same signals. As shown in FIG. 48 (c), the circulating current command I ₀₁ * can be surely limited to the minimum circulating current command I _0b specified by the circulating current specified value setter.

FIG. 49 is a block diagram showing a modified example 9 of the second embodiment. FIG. 49 shows that when the output of the individual reactive power control circuit 38 is positive, it is output as it is, and when it is negative, it is zero output in order to securely limit the lower limit of the circulating current command value and ensure the characteristics of the circulating current type cycloconverter. A lower limit limiter circuit 65 is added, and the output I ₀₁ ** is added to the output I _0b of the circulating current specified value setter 66 by an adder 67 to obtain a circulating current command. Therefore, at least the circulating current set by circulating current specified value setter 66 flows, so that the characteristics of the circulating current type cycloconverter can be reliably ensured.

FIG. 50 shows an example of the operation modes of the parallel operation device for the cycloconverter shown in FIG. In FIG. 50,
The same reference numerals as those in FIG. 32 indicate the same signals. As shown in FIG. 50 (c), the circulating current command I ₀₁ * of the individual reactive power control circuit 38 is limited to a positive signal, and the circulating current command is greater than the output I _0b of the circulating current specified value setter 66. The value can be secured.

FIG. 51 is a block diagram showing a modification 10 of the second embodiment. FIG. 51 shows that an upper limiter circuit 70 is added to the output of the operation control compensation circuit 35 for individual reactive power command in order to reliably limit the upper limit of the individual reactive power compensation amount, and the lower limit of the circulating current command value is ensured. A diode 71 is used for the output of the individual reactive power control circuit 38 in order to secure the characteristics of the limiting and circulating current type cycloconverter. or circuit configuration,
A circulating current specified value setter 72 is added. Therefore, the maximum reactive power compensation amount can be limited, and the circulating current can be limited. Therefore, it is not necessary to increase the capacity of the cycloconverter to the capacity of the load more than necessary, so that inexpensive equipment can be provided. Further, since the minimum circulating current can be controlled and secured, the circulating current is not interrupted, and the characteristics as the circulating current type cycloconverter can be secured.

FIG. 52 shows an example of the operation modes of the parallel operation device for the cycloconverter shown in FIG. In FIG. 52,
The same reference numerals as those in FIG. 32 indicate the same signals.

FIG. 53 is a block diagram showing a modified example 11 of the second embodiment. FIG. 53 shows that an upper limiter circuit 75 is added to the output of 35 for individual reactive power command in order to securely limit the upper limit of the individual reactive power compensation amount, and the lower limit of the circulating current command value is surely restricted to circulate. in order to ensure the characteristics of the current type cycloconverter, is directly output when the output of the individual reactive power control circuit 38 is positive when a negative adds a lower limiter circuit 76 to zero output, the output I ₀₁ * An output I _0b of the circulating current specified value setting unit 77 is added to * by an adder 78 to _obtain a circulating current command. Therefore, the maximum reactive power compensation amount can be limited, and the circulating current can be limited. Therefore, it is not necessary to increase the capacity of the cycloconverter to the capacity of the load more than necessary, so that inexpensive equipment can be provided. Further, since the minimum circulating current can be controlled and secured, the circulating current is not interrupted, and the characteristics as the circulating current type cycloconverter can be secured.

FIG. 54 shows an example of the operation modes of the parallel operation device for the cycloconverter shown in FIG. In FIG. 54,
The same reference numerals as those in FIG. 32 indicate the same signals.

FIG. 55 is a block diagram showing a modified example 12 of the second embodiment. FIG. 55 shows that in order to reliably limit the upper limit of the individual reactive power compensation amount and to reliably specify the lower limit of the circulating current command value, and to limit the control range of the individual reactive power command and speed up the response, An upper and lower limit limiter circuit 81 is added to the output of the arithmetic control compensation circuit 35, and the output of the individual reactive power control circuit 38 is added to ensure the characteristics of the circulating current type cycloconverter by securely limiting the lower limit of the circulating current command value. Using diode 82, max. or circuit configuration, and a circulating current specified value setter 83 is added.

FIG. 56 shows an example of the operation modes of the parallel operation device for the cycloconverter shown in FIG. In FIG. 56,
The same reference numerals as those in FIG. 32 indicate the same signals.

FIG. 57 is a block diagram showing a modification 13 of the second embodiment. FIG. 57 shows that the upper limit of the individual reactive power compensation amount is surely limited, the lower limit of the circulating current command value is reliably regulated, and the control range of the individual reactive power command is limited to speed up the control response. An upper / lower limit limiter circuit 86 is added to the output of the calculation control compensation circuit 35 for the individual reactive power command, and the lower limit of the circulating current command value is surely limited to ensure the characteristics of the circulating current type cycloconverter. The lower limit of the lower limit limiter circuit 86 is set to zero, and the individual reactive power control circuit 38 can be output. When it is positive, it is output as it is, and when it is negative, a lower limit limiter circuit 87 is added, and its output I ₀₁ ** is added. The output I _0b of the circulating current specified value setter 88 is added by an adder 89 to give a circulating current command.

FIG. 58 shows an example of the operation modes of the parallel operation device for the cycloconverter shown in FIG. In FIG. 58,
The same reference numerals as those in FIG. 32 indicate the same signals.

Example 3. The third embodiment of the present invention will be described below with reference to the drawings. In FIG. 59, 10a, 10b, and 10c are individual phase-advancing capacitors for compensating for the minimum delay reactive power generated by each cycloconverter 1 to 3, 11, 12, 13, and 14, respectively.
Is a switch, 17, 18 and 19 are cycloconverters 1 to 3,
And phase-advancing capacitors 10a to 10c Current transformers for measuring instruments for detecting individual input currents, 20, 21, 22 are total reactive power at the receiving end of the AC power supply BUS and each cycloconverter 1
˜3 Circulating current command generation circuit for controlling individual generated reactive power, and 23 is a cycloconverter parallel operation apparatus according to the present invention having the above-mentioned configurations.

A detailed block diagram of the circulating current command generation circuit 20 is shown in FIG. In FIG. 60, 24 is an instrument transformer 15, and a receiving end voltage detected by the instrument current transformer 16, and a total reactive power detection circuit that detects total reactive power from the current, and 25 is a total reactive power detection circuit. Introduces the measured reactive power to be detected, and in the case of delayed reactive power, no output is generated in the predetermined dead zone region, and output is generated when the dead zone is exceeded, and in the case of advanced reactive power, according to the advanced reactive power. A reference numeral 35 is a calculation control compensating circuit for proportionally amplifying or integral amplifying the deviation detection value Qtf of the total reactive power which is the output of this limiter circuit, and generating a reactive power reference command for each cycloconverter. , 36 is an individual reactive power detection circuit that detects the reactive power generated by each cycloconverter from the voltage and current detected by the instrument transformer 15 and the instrument current transformer 17, and 37 is the arithmetic control Cycloconverter to generate the 償回 passage 35 individual generator reactive power reference Qi
A comparator for comparing * and the individual reactive power detection value Qi detected by the individual reactive power detection circuit 36, and a generated reactive power control circuit 38 for proportionally amplifying or integral amplifying the deviation ε1 output from the comparator 37.

The load current control means and the circulating current control means are controlled in the same manner as in the prior art, but the method of reactive power control at the power receiving end is different and will be described below. As shown in FIG. 59, the cycloconverters 1 to 3 and the input transformer 7 to
The switch 9 is connected to the AC power supply BUS in parallel by switches 12 to 14. Further, as in the case where only the cycloconverter 1 is shown in FIG. 60, each cycloconverter has a detection function and a control function of the total reactive power at the power receiving end. If it becomes abnormal, it does not affect the control of other cycloconverters and total reactive power.

Next, the control method of the total reactive power will be described for the cycloconverter 1 with reference to FIG. The total reactive power detection circuit 24 receives the voltage and current detection signals of the power receiving end from the instrument transformer 15 and the instrument current transformer 16, and detects the total reactive power at the power receiving end. Total reactive power detection circuit
The total reactive power Qt detected by 24 is input to the limiter circuit 25. When the actually measured reactive power detected by the total reactive power detection circuit 24 is delayed reactive power, the limiter circuit 25 determines the total reactive current according to the management value Qt *. No output is generated in the dead zone area, and a negative signal is generated when the dead zone area is exceeded.
In the case of advanced reactive power, a positive signal corresponding to the reactive power is generated. The output Qtf of the limiter circuit 25 is introduced into the operation control compensation circuit 35, and proportional amplification or integral amplification is performed to output a reactive power reference command for each cycloconverter. That is, the individual generated reactive power command Qi * is increased / decreased by the deviation between the control value Qt * of the total reactive power and the detected value Qt of the total reactive power to control the reactive power at the power receiving end. The arithmetic control compensating circuit 35 is given a preset no-load reactive power compensation amount as an initial value.

Next, the individual reactive power detection circuit 36 detects the reactive power Qi generated by the cycloconverter 1 based on the voltage and current signals obtained from the instrument transformer 15 and the instrument current transformer 17. The generated reactive power Qi detected by the individual reactive power detection circuit 36 and the control value Qt * of the total reactive power output by the arithmetic control compensation circuit 35 are compared by a comparator 37 with a deviation ε1 =
Qi * -Qi is taken and input to the individually-generated reactive power control circuit 38 formed of a proportional-integral circuit. The individually generated reactive power control circuit 38 is the cycloconverter 1 according to the deviation ε1.
The circulating current command I ₀₁ * is output to the circulating current control circuit I ₀ C1 to control the circulating current of the cycloconverter 1 as in the conventional case. Since the generated reactive power Qi detected by the individual reactive power detection circuit 36 directly detects the delayed reactive power generated by the cycloconverter 1 of the load and the fluctuation component, it is possible to improve the response of the individually generated reactive power control circuit 38. become.

FIG. 61 is a characteristic diagram showing an example of the operation mode of the apparatus of FIG. In FIG. 61 (a), Qcap is the leading reactive power that the phase-advancing capacitor 10 takes, and Qc / cL is the delayed reactive power that the entire cycloconverter takes. When the circulating current of the cycloconverter 1 is the minimum value (reactive power). Reactive power (when compensation is not performed), Qi * is the individually generated reactive power command of the cycloconverter 1, and Qc
/ CL is generated to compensate for the amount missing from Qcap. Here, the central portion of Qi * is the portion where the minimum circulating current is flowing to the cycloconverter 1, and Qi * does not fall below this. Also, FIG. 61 (b)
Qtf is the reactive power at the receiving end, and the delayed reactive power Qc / cL increases due to an increase in the load current and the circulating current, and the advanced reactive power Qca taken by the phase advance capacitor 10 is
The waveform is the part that exceeds p.

FIG. 61 (c) shows the circulating current command I ₀₁ * and the generated reactive power Qi when the load current Il1 of the cycloconverter 1 changes as shown by the broken line. As is clear from the figure, the circulating current command I ₀₁ * changes according to the individually generated reactive power command Qi *, but the load current Il1 changes as shown by the broken line, so that the generated reactive power Qi of the cycloconverter 1 is changed. Has a waveform obtained by adding Il1 and I ₀₁ * as shown by the alternate long and short dash line. Further, FIG. 61 (d) shows the circulating current command I _0n * and the generated reactive power Qi when the load current Iln of the cycloconverter 3 changes as shown by the broken line. As is clear from the figure, the circulating current command I _0n * changes according to the individually generated reactive power command Qi *, but since the load current Iln changes as shown by the broken line, the generated reactive power Qi of the cycloconverter 1 is changed. Has a waveform obtained by adding Il1 and I ₀₁ * as shown by the alternate long and short dash line.

That is, when Qc / cL <Qcap, by increasing the circulating current of each cycloconverter,
It can be set to Qtf = 0. On the other hand, Qc / cL> Q
In the case of cap, Qtf = 0 can be set by reducing the circulating current of each cycloconverter.

FIG. 62 is a block diagram showing a first modification of the third embodiment. In FIG. 62, 39 is an upper limiter circuit that limits the output of the arithmetic control compensation circuit 35. The upper limit limiter circuit 39 can reliably limit the upper limit of the individually generated reactive power command generated by the calculation control compensation circuit 35. Therefore, the maximum reactive power compensation amount of the cycloconverter 1 can be limited, and the circulating current can be limited. Therefore, it is not necessary to increase the capacity of the cycloconverter 1 with respect to the capacity of the load more than necessary. it can.

FIG. 63 shows an example of the operation modes of the parallel operation device for the cycloconverter shown in FIG. In Figure 63,
The same reference numerals as in FIG. 61 indicate the same signals. The individually generated reactive power command Qi * in FIG. 63 (a) initially exceeds the limit value of the upper limit limiter circuit 39, but the circulating current command I ₀₁ shown in FIG. 63 (c).
It is restricted like *.

FIG. 64 is a block diagram showing a second modification of the third embodiment. In FIG. 64, reference numeral 42 is a lower limiter circuit that limits the output of the arithmetic control compensation circuit 35. The lower limit limiter circuit 42 can reliably limit the lower limit of the individually generated reactive power command generated by the calculation control compensation circuit 35. Therefore, since the minimum individually generated reactive power command by the cycloconverter 1 can be secured, the circulating current can be regulated so as not to be interrupted, and the characteristics of the circulating current type cycloconverter can be reliably secured.

FIG. 65 shows an example of operation modes of the parallel operation device for the cycloconverter shown in FIG. In FIG. 65,
The same reference numerals as in FIG. 61 indicate the same signals. In FIG. 65 (d), it can be seen that the load current Iln becomes the minimum and the generated reactive power also decreases, but the lower limit limiter circuit 42 surely secures the lower limit value of the generated reactive power.

FIG. 66 is a block diagram showing a third modification of the third embodiment. In FIG. 66, 45 is an upper / lower limit limiter circuit that limits the output of the arithmetic control compensation circuit 35. The upper and lower limit limiter circuit 45 can reliably limit the upper and lower limits of the individually generated reactive power command generated by the calculation control compensation circuit 35. Therefore, the maximum reactive power compensation amount of the cycloconverter 1 can be limited, and the circulating current can be limited. Therefore, it is not necessary to increase the capacity of the cycloconverter 1 with respect to the capacity of the load more than necessary. it can. Further, since the minimum individually generated reactive power command by the cycloconverter 1 can be secured, the circulating current can be regulated so as not to be interrupted, and the characteristics of the circulating current type cycloconverter can be reliably secured. Furthermore, since the control range of the individually generated reactive power is specified, the control response, that is, the individually generated reactive power command Q
The control output response of i * can be improved.

FIG. 67 shows an example of operation modes of the parallel operation device for the cycloconverter shown in FIG. In FIG. 67,
The same reference numerals as in FIG. 61 indicate the same signals.

FIG. 68 is a block diagram showing a modified example 4 of the third embodiment. In FIG. 68, 48 is an individual reactive power control circuit
This is a lower limiter circuit that limits the output of 38. The lower limit limiter circuit 48 can reliably limit the lower limit of the circulating current command generated by the individual reactive power control circuit 38. Therefore, the minimum circulating current command can be specified so that the circulating current of the cycloconverter 1 is not interrupted, and the characteristics of the circulating current type cycloconverter can be reliably ensured.

FIG. 69 shows an example of the operation modes of the parallel operation device for the cycloconverter shown in FIG. In FIG. 69,
The same reference numerals as in FIG. 61 indicate the same signals. As shown in FIGS. 69 (c) and 69 (d), the circulating current commands I ₀₁ *, I _0n * can be reliably limited to the lower limit of the minimum circulating current command.

FIG. 70 is a block diagram showing a modified example 5 of the third embodiment. In FIG. 70, 51 is an individual reactive power control circuit
It is an upper limiter circuit that limits the output of 38. The upper limit limiter circuit 51 can reliably limit the lower limit of the circulating current command generated by the individual reactive power control circuit 38. Therefore, the upper limit of the circulating current command of the cycloconverter 1 can be limited, so that the capacity of the cycloconverter 1 does not have to be made larger than necessary to the capacity of the load, and an inexpensive device can be obtained.

FIG. 71 shows an example of the operation modes of the parallel operation device for the cycloconverter shown in FIG. In FIG. 71,
The same reference numerals as in FIG. 61 indicate the same signals. As shown in FIGS. 71 (c) and 71 (d), the circulating current commands I ₀₁ *, I _0n * can be reliably limited to the upper limit of the maximum circulating current command.

FIG. 72 is a block diagram showing a modification 6 of the third embodiment. In FIG. 72, 54 is an individual reactive power control circuit
An upper and lower limiter circuit that limits the output of 38. The upper and lower limit limiter circuit 54 can reliably limit the upper and lower limits of the circulating current command generated by the individual reactive power control circuit 38. Therefore, the minimum circulating current command can be specified so that the circulating current of the cycloconverter 1 is not interrupted, and the characteristics of the circulating current type cycloconverter can be reliably ensured. Further, since the upper limit of the circulating current command of the cycloconverter 1 can be limited, the capacity of the cycloconverter 1 does not have to be made larger than necessary to the capacity of the load, so that an inexpensive device can be obtained. Further, since the control range of the circulating current is limited, the influence on the fluctuation of the load current can be suppressed.

FIG. 73 shows an example of the operation modes of the parallel operation device for the cycloconverter shown in FIG. In FIG. 73,
The same reference numerals as in FIG. 61 indicate the same signals. As shown in FIGS. 73 (c) and (d), the circulating current commands I ₀₁ *, I _0n * can be reliably limited to the lower limit of the minimum circulating current command and the upper limit of the maximum circulating current command.

FIG. 74 is a block diagram showing a modified example 7 of the third embodiment. In FIG. 74, 57 is an upper limiter circuit that limits the output of the generated reactive power reference command integrator 35.
The upper limit limiter circuit 57 can reliably limit the upper limit of the individually generated reactive power command generated by the calculation control compensation circuit 35. Reference numeral 58 is a lower limiter circuit that limits the output of the individual reactive power control circuit 38. The lower limit limiter circuit 58 can reliably limit the lower limit of the circulating current command generated by the individual reactive power control circuit 38. Therefore, the maximum reactive power compensation amount of the cycloconverter 1 can be limited, and the circulating current can be limited, so that the capacity of the cycloconverter 1 does not have to be made larger than necessary relative to the capacity of the load.
Can be an inexpensive device. Further, the minimum circulating current command can be specified so that the circulating current of the cycloconverter 1 is not interrupted, and the characteristics of the circulating current type cycloconverter can be reliably ensured.

FIG. 75 shows an example of the operation modes of the parallel operation device for the cycloconverter shown in FIG. In FIG. 75,
The same reference numerals as in FIG. 61 indicate the same signals. As shown in FIGS. 75 (c) and (d), the circulating current commands I ₀₁ *, I _0n * can be surely limited to the lower limit of the minimum circulating current command, and the maximum reactive power compensation amount maxΔQ can be limited. Circulating current is limited.

FIG. 76 is a block diagram showing a modified example 8 of the third embodiment. FIG. 76 shows that the diode 61 is used as the output of the individual reactive power control circuit 38 in order to securely limit the lower limit of the circulating current command value and ensure the characteristics of the circulating current type cycloconverter. or circuit configuration, circulating current specified value setter 62
Is provided. Therefore, even if the individual reactive power control circuit 38 outputs a negative signal, the minimum circulating current can be controlled and secured, and the circulating current is not interrupted, so that the characteristics of the circulating current type cycloconverter can be reliably secured.

FIG. 77 shows an example of the operation modes of the parallel operation device for the cycloconverter shown in FIG. In FIG. 77,
The same reference numerals as in FIG. 61 indicate the same signals. As shown in FIG. 77 (c), the circulating current command I ₀₁ * can be reliably limited to the minimum circulating current command I _0b defined by the circulating current specified value setter.

FIG. 78 is a block diagram showing a modified example 9 of the third embodiment. FIG. 78 shows that, in order to reliably limit the lower limit of the circulating current command value and ensure the characteristics of the circulating current type cycloconverter, when the output of the individual reactive power control circuit 38 is positive, it is output as it is, and when it is negative, it is zero output. A lower limit limiter circuit 65 is added, and the output I ₀₁ ** is added to the output I _0b of the circulating current specified value setter 66 by an adder 67 to obtain a circulating current command. Therefore, at least the circulating current set by circulating current specified value setter 66 flows, so that the characteristics of the circulating current type cycloconverter can be reliably ensured.

FIG. 79 shows an example of operation modes of the parallel operation device for the cycloconverter shown in FIG. In FIG. 79,
The same reference numerals as in FIG. 61 indicate the same signals. As shown in FIG. 79 (c), the circulating current command I ₀₁ * of the individual reactive power control circuit 38 is limited to a positive signal, and the circulating current command is equal to or more than the output I _0b of the circulating current specified value setter 66. The value can be secured.

FIG. 80 is a block diagram showing a modification 10 of the third embodiment. FIG. 80 shows that, in order to reliably limit the upper limit of the individual reactive power compensation amount, an upper limiter circuit 70 is added to the output of the arithmetic control compensation circuit 35 for the individual reactive power command, and the lower limit of the circulating current command value is ensured. A diode 71 is used for the output of the individual reactive power control circuit 38 in order to secure the characteristics of the limiting and circulating current type cycloconverter. or circuit configuration,
A circulating current specified value setter 72 is added. Therefore, the maximum reactive power compensation amount can be limited, and the circulating current can be limited. Therefore, it is not necessary to increase the capacity of the cycloconverter to the capacity of the load more than necessary, so that inexpensive equipment can be provided. Further, since the minimum circulating current can be controlled and secured, the circulating current is not interrupted, and the characteristics as the circulating current type cycloconverter can be secured.

FIG. 81 shows an example of operation modes of the parallel operation device for the cycloconverter shown in FIG. In FIG. 81,
The same reference numerals as in FIG. 61 indicate the same signals.

FIG. 82 is a block diagram showing a modification 11 of the third embodiment. FIG. 82 shows that an upper limiter circuit 75 is added to the output of the arithmetic control compensation circuit 35 for individual reactive power command in order to reliably limit the upper limit of the individual reactive power compensation amount, and the lower limit of the circulating current command value is ensured. In order to secure the characteristics of the circulating current type cycloconverter by limiting to, the output of the individual reactive power control circuit 38 is output as it is when the output is positive, and a lower limit limiter circuit 76 that makes zero output when it is negative is added. Output I ₀₁ **
Further, the output I _0b of the circulating current specified value setting unit 77 is added by the adder 78 to _obtain the circulating current command. Therefore, the maximum reactive power compensation amount can be limited, and the circulating current can be limited. Therefore, it is not necessary to increase the capacity of the cycloconverter to the capacity of the load more than necessary, so that inexpensive equipment can be provided. Further, since the minimum circulating current can be controlled and secured, the circulating current is not interrupted, and the characteristics as the circulating current type cycloconverter can be secured.

FIG. 83 shows an example of operation modes of the parallel operation device for the cycloconverter shown in FIG. In FIG. 83,
The same reference numerals as in FIG. 61 indicate the same signals.

FIG. 84 is a block diagram showing a modified example 12 of the third embodiment. FIG. 84 shows that in order to reliably limit the upper limit of the individual reactive power compensation amount and to reliably specify the lower limit of the circulating current command value, and to limit the control range of the individual reactive power command and speed up the response, An upper and lower limit limiter circuit 81 is added to the output of the arithmetic control compensation circuit 35, and the output of the individual reactive power control circuit 38 is added to ensure the characteristics of the circulating current type cycloconverter by securely limiting the lower limit of the circulating current command value. Using diode 82, max. or circuit configuration, and a circulating current specified value setter 83 is added.

FIG. 85 shows an example of the operation modes of the parallel operation device for the cycloconverter shown in FIG. In FIG. 85,
The same reference numerals as in FIG. 61 indicate the same signals.

FIG. 86 is a block diagram showing a modification 13 of the third embodiment. FIG. 86 shows that in order to reliably limit the upper limit of the individual reactive power compensation amount, to reliably specify the lower limit of the circulating current command value, and to limit the control range of the individual reactive power command and speed up the control response. An upper / lower limit limiter circuit 86 is added to the output of the calculation control compensation circuit 35 for the individual reactive power command, and the lower limit of the circulating current command value is surely limited to ensure the characteristics of the circulating current type cycloconverter. The lower limit of the lower limit limiter circuit 86 is set to zero, and the individual reactive power control circuit 38 can be output. When it is positive, it is output as it is, and when it is negative, a lower limit limiter circuit 87 is added, and its output I ₀₁ ** is added. The output I _0b of the circulating current specified value setter 88 is added by an adder 89 to give a circulating current command.

FIG. 87 shows an example of the operation modes of the parallel operation device for the cycloconverter shown in FIG. In FIG. 87,
The same reference numerals as in FIG. 61 indicate the same signals.

[0124]

As described above, according to the parallel operation device for the cycloconverter of the present invention, the generated reactive power control system is provided for each cycloconverter, and the measured value of the total reactive power and the total reactive power management value are combined. Since the individual reactive power command is derived from the deviation and the circulating current of each cycloconverter is controlled based on the individual reactive power command,
Circulating current can be regulated, total reactive power control can be controlled stably, and control with fast response can be realized.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a parallel operation device for a cycloconverter according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing a parallel operation device for a cycloconverter according to a first embodiment of the present invention.

FIG. 3 is a characteristic diagram showing operation modes of the parallel operation device for the cycloconverter according to the first embodiment of the present invention.

FIG. 4 is a block diagram showing a cycloconverter parallel operation apparatus according to a first modification of the first embodiment of the present invention.

FIG. 5 is a characteristic diagram showing operation modes of a parallel operation device for a cycloconverter according to a first modification of the first embodiment of the present invention.

FIG. 6 is a block diagram showing a cycloconverter parallel operation apparatus according to a second modification of the first embodiment of the present invention.

FIG. 7 is a characteristic diagram showing operation modes of a parallel operation device for a cycloconverter according to a second modification of the first embodiment of the present invention.

FIG. 8 is a block diagram showing a parallel operating device for a cycloconverter according to a third modification of the first embodiment of the present invention.

FIG. 9 is a characteristic diagram showing operation modes of a parallel operation device for a cycloconverter according to a third modification of the first embodiment of the present invention.

FIG. 10 is a block diagram showing a parallel operation device for a cycloconverter according to a fourth modification of the first embodiment of the present invention.

FIG. 11 is a characteristic diagram showing operation modes of a parallel operation device for a cycloconverter according to a fourth modification of the first embodiment of the present invention.

FIG. 12 is a block diagram showing a parallel operating device for a cycloconverter according to a fifth modification of the first embodiment of the present invention.

FIG. 13 is a characteristic diagram showing operation modes of a parallel operation device for a cycloconverter according to Modification 5 of Embodiment 1 of the present invention.

FIG. 14 is a block diagram showing a parallel operating device for a cycloconverter according to a sixth modification of the first embodiment of the present invention.

FIG. 15 is a characteristic diagram showing operation modes of a parallel operation device for a cycloconverter according to Modification 6 of Embodiment 1 of the present invention.

FIG. 16 is a block diagram showing a parallel operating device for a cycloconverter according to a seventh modification of the first embodiment of the present invention.

FIG. 17 is a characteristic diagram showing operation modes of a parallel operation device for a cycloconverter according to Modification 7 of Embodiment 1 of the present invention.

FIG. 18 is a block diagram showing a parallel operating device for a cycloconverter according to a modified example 8 of the first embodiment of the present invention.

FIG. 19 is a characteristic diagram showing operation modes of a parallel operation device for a cycloconverter according to Modification 8 of Embodiment 1 of the present invention.

FIG. 20 is a block diagram showing a parallel operating device for a cycloconverter according to a ninth modification of the first embodiment of the present invention.

FIG. 21 is a characteristic diagram showing operation modes of a parallel operation device for a cycloconverter according to Modification 9 of Embodiment 1 of the present invention.

FIG. 22 is a block diagram showing a parallel operating device for a cycloconverter according to a tenth modification of the first embodiment of the present invention.

FIG. 23 is a characteristic diagram showing operation modes of a parallel operation device for a cycloconverter according to Modification 10 of Example 1 of the present invention.

FIG. 24 is a block diagram showing a parallel operating device for a cycloconverter according to Modification 11 of Embodiment 1 of the present invention.

FIG. 25 is a characteristic diagram showing operation modes of a parallel operation device for a cycloconverter according to Modification 11 of Example 1 of the present invention.

FIG. 26 is a block diagram showing a parallel operating device for a cycloconverter according to Modification 12 of Embodiment 1 of the present invention.

FIG. 27 is a characteristic diagram showing operation modes of a parallel operation device for a cycloconverter according to Modification 12 of Embodiment 1 of the present invention.

FIG. 28 is a block diagram showing a cycloconverter parallel operation apparatus according to Modification 13 of Embodiment 1 of the present invention.

FIG. 29 is a characteristic diagram showing operation modes of a parallel operation device for a cycloconverter according to Modification 13 of Example 1 of the present invention.

FIG. 30 is a configuration diagram showing a parallel operation device for a cycloconverter according to a second embodiment of the present invention.

FIG. 31 is a block diagram showing a parallel operating device for a cycloconverter according to a second embodiment of the present invention.

FIG. 32 is a characteristic diagram showing operation modes of a parallel operation device for a cycloconverter according to a second embodiment of the present invention.

FIG. 33 is a block diagram showing a parallel operating device for a cycloconverter according to a first modification of the second embodiment of the present invention.

FIG. 34 is a characteristic diagram showing operation modes of a parallel operation device for a cycloconverter according to a first modification of the second embodiment of the present invention.

FIG. 35 is a block diagram showing a parallel operating device for a cycloconverter according to a second modification of the second embodiment of the present invention.

FIG. 36 is a characteristic diagram showing operation modes of a parallel operation device for a cycloconverter according to a second modification of the second embodiment of the present invention.

FIG. 37 is a block diagram showing a parallel operating device for a cycloconverter according to a third modification of the second embodiment of the present invention.

FIG. 38 is a characteristic diagram showing operation modes of a parallel operation device for a cycloconverter according to Modification 3 of Embodiment 2 of the present invention.

FIG. 39 is a block diagram showing a parallel operating device for a cycloconverter according to a fourth modification of the second embodiment of the present invention.

FIG. 40 is a characteristic diagram showing operation modes of a parallel operation device for a cycloconverter according to Modification 4 of Embodiment 2 of the present invention.

FIG. 41 is a block diagram showing a parallel operating device for a cycloconverter according to a fifth modification of the second embodiment of the present invention.

FIG. 42 is a characteristic diagram showing an operation mode of a parallel converter for a cycloconverter according to a fifth modification of the second embodiment of the present invention.

FIG. 43 is a block diagram showing a parallel operating device for a cycloconverter according to a sixth modification of the second embodiment of the present invention.

FIG. 44 is a characteristic diagram showing operation modes of a parallel operation device for a cycloconverter according to Modification 6 of Embodiment 2 of the present invention.

FIG. 45 is a block diagram showing a parallel operating device for a cycloconverter according to a modification 7 of the second embodiment of the present invention.

FIG. 46 is a characteristic diagram showing operation modes of a parallel operation device for a cycloconverter according to Modification 7 of Embodiment 2 of the present invention.

FIG. 47 is a block diagram showing a parallel operating device for a cycloconverter according to a modified example 8 of the second embodiment of the present invention.

FIG. 48 is a characteristic diagram showing operation modes of a parallel operation device for a cycloconverter according to Modification 8 of Embodiment 2 of the present invention.

FIG. 49 is a block diagram showing a parallel operating device for a cycloconverter according to a ninth modification of the second embodiment of the present invention.

FIG. 50 is a characteristic diagram showing operation modes of a parallel operation device for a cycloconverter according to a ninth modification of the second embodiment of the present invention.

FIG. 51 is a block diagram showing a parallel operating device for a cycloconverter according to a tenth modification of the second embodiment of the present invention.

FIG. 52 is a characteristic diagram showing operation modes of a parallel operation device for a cycloconverter according to Modification 10 of Example 2 of the present invention.

FIG. 53 is a block diagram showing a parallel operating device for a cycloconverter according to Modification 11 of Embodiment 2 of the present invention.

FIG. 54 is a characteristic diagram showing operation modes of a parallel operation device for a cycloconverter according to Modification 11 of Embodiment 2 of the present invention.

FIG. 55 is a block diagram showing a parallel operating device for a cycloconverter according to Modification 12 of Embodiment 2 of the present invention.

FIG. 56 is a characteristic diagram showing operation modes of a parallel operation device for a cycloconverter according to Modification 12 of Embodiment 2 of the present invention.

FIG. 57 is a block diagram showing a cycloconverter parallel operation apparatus according to Modification 13 of Embodiment 2 of the present invention.

FIG. 58 is a characteristic diagram showing operation modes of a parallel operation device for a cycloconverter according to Modification 13 of Embodiment 2 of the present invention.

FIG. 59 is a configuration diagram showing a parallel operation device for a cycloconverter according to a third embodiment of the present invention.

FIG. 60 is a block diagram showing a parallel operating device for a cycloconverter according to a third embodiment of the present invention.

FIG. 61 is a characteristic diagram showing operation modes of the parallel operation device for the cycloconverter according to the third embodiment of the present invention.

FIG. 62 is a block diagram showing a parallel operating device for a cycloconverter according to a first modification of the third embodiment of the present invention.

FIG. 63 is a characteristic diagram showing operation modes of a parallel operation device for a cycloconverter according to a first modification of the third embodiment of the present invention.

FIG. 64 is a block diagram showing a parallel operating device for a cycloconverter according to a second modification of the third embodiment of the present invention.

FIG. 65 is a characteristic diagram showing operation modes of a parallel operation device for a cycloconverter according to a second modification of the third embodiment of the present invention.

FIG. 66 is a block diagram showing a parallel operating device for a cycloconverter according to a third modification of the third embodiment of the present invention.

FIG. 67 is a characteristic diagram showing operation modes of a parallel operation device for a cycloconverter according to Modification 3 of Embodiment 3 of the present invention.

FIG. 68 is a block diagram showing a parallel operating device for a cycloconverter according to a fourth modification of the third embodiment of the present invention.

FIG. 69 is a characteristic diagram showing operation modes of the parallel operation device for the cycloconverter according to the fourth modification of the third embodiment of the present invention.

FIG. 70 is a block diagram showing a parallel operating device for a cycloconverter according to a fifth modification of the third embodiment of the present invention.

FIG. 71 is a characteristic diagram showing operation modes of a parallel operation device for a cycloconverter according to a fifth modification of the third embodiment of the present invention.

FIG. 72 is a block diagram showing a parallel operating device for a cycloconverter according to a sixth modification of the third embodiment of the present invention.

FIG. 73 is a characteristic diagram showing operation modes of a parallel operation device for a cycloconverter according to Modification 6 of Embodiment 3 of the present invention.

FIG. 74 is a block diagram showing a parallel operating device for a cycloconverter according to a seventh modification of the third embodiment of the present invention.

FIG. 75 is a characteristic diagram showing operation modes of a parallel operation device for a cycloconverter according to Modification 7 of Embodiment 3 of the present invention.

FIG. 76 is a block diagram showing a cycloconverter parallel operation apparatus according to a modified example 8 of the embodiment 3 of the present invention.

FIG. 77 is a characteristic diagram showing operation modes of a parallel operation device for a cycloconverter according to Modification 8 of Embodiment 3 of the present invention.

FIG. 78 is a block diagram showing a parallel operating device for a cycloconverter according to a ninth modification of the third embodiment of the present invention.

FIG. 79 is a characteristic diagram showing operation modes of a parallel operation device for a cycloconverter according to Modification 9 of Example 3 of the present invention.

FIG. 80 is a block diagram showing a parallel operating device for a cycloconverter according to a tenth modification of the third embodiment of the present invention.

FIG. 81 is a characteristic diagram showing operation modes of a parallel operation device for a cycloconverter according to Modification 10 of Example 3 of the present invention.

FIG. 82 is a block diagram showing a parallel operating device for a cycloconverter according to Modification 11 of Embodiment 3 of the present invention.

FIG. 83 is a characteristic diagram showing operation modes of a parallel operation device for a cycloconverter according to Modification 11 of Example 3 of the present invention.

FIG. 84 is a block diagram showing a parallel operating device for a cycloconverter according to Modification 12 of Embodiment 3 of the present invention.

FIG. 85 is a characteristic diagram showing operation modes of a parallel operation device for a cycloconverter according to Modification 12 of Example 3 of the present invention.

FIG. 86 is a block diagram showing a parallel operating device for a cycloconverter according to a modification 13 of the third embodiment of the present invention.

FIG. 87 is a characteristic diagram showing operation modes of a parallel operation device for a cycloconverter according to Modification 13 of Example 3 of the present invention.

[Fig. 88] Fig. 88 is a configuration diagram showing a parallel operation device of a conventional cycloconverter.

FIG. 89 is a block diagram showing a conventional parallel converter for a cycloconverter.

FIG. 90 is a block diagram showing a conventional integrated reactive power control circuit.

FIG. 91 is a characteristic diagram showing a limiter characteristic of a conventional total reactive power control circuit.

[Explanation of symbols]

1 cycloconverter 2 cyclo converter 3 cyclo converter 10-phase capacitor 15 Instrument transformer 16 Current transformer for instrument 17 Instrument Current Transformer 24 Total reactive power detection circuit 25 limiter circuit 35 Arithmetic control compensation circuit 36 Individual reactive power detection circuit 38 Individual reactive power control circuit

─────────────────────────────────────────────────── --Continued from the front page (56) References JP-A-4-361308 (JP, A) JP-A-6-178540 (JP, A) JP-A-58-60328 (JP, A) (58) Field (Int.Cl. ⁷ , DB name) H02M 5/27

Claims (6)

(57) [Claims] 1. A plurality of loads each of which is supplied with power from a plurality of circulating current type cycloconverters connected in parallel via a power receiving end of an AC power supply, and a phase advance which is collectively connected to the power receiving end of the AC power supply. A capacitor, a load current control circuit for controlling the load current of the cycloconverter, a circulating current control circuit for controlling the circulating current of the cycloconverter, a total reactive power detector for detecting reactive power at the receiving end, and the cycloconverter individually When the actual reactive power detected by the integrated reactive power detection circuit is a delayed reactive power, the delayed reactive power does not generate an output in the predetermined dead zone region and the dead zone is detected. A limiter circuit that generates an output in accordance with the progress reactive power, and an output in accordance with the advance reactive power in the case of advanced reactive power. Computation control compensation circuit that generates an individual reactive power command according to the output of the road, based on the deviation between the individual reactive power command generated by this calculation control compensation circuit and the reactive power detected by the individual reactive power detector 1. A parallel operation device for a cycloconverter, further comprising: an individual reactive power control circuit that gives a circulating current command to the circulating current control circuit that controls the circulating current of the cycloconverter. 2. A plurality of loads, each of which is supplied with power from a plurality of circulating current type cycloconverters connected in parallel via a power receiving end of the AC power supply, and a batch insertion collectively connected to the power receiving end of the AC power supply. Phase-advancing capacitors, individual phase-advancing capacitors respectively connected to power supply systems for the plurality of circulating current type cycloconverters, a load current control circuit for controlling the load current of the cycloconverter, and a circulating current of the cycloconverter. Circulating current control circuit, integrated reactive power detector that detects reactive power at the receiving end, individual reactive power detector that detects reactive power generated individually by the cycloconverter, actual reactive detected by the integrated reactive power detection circuit When the power is delayed reactive power, the delayed reactive power does not generate an output in the predetermined dead zone, but outputs when the dead zone is exceeded. A limiter circuit that generates an output according to the advanced reactive power when the advanced reactive power is generated,
A calculation control compensation circuit that generates an individual reactive power command according to the output of this limiter circuit, based on the deviation between the individual reactive power command generated by this calculation control compensation circuit and the reactive power detected by the individual reactive power detector. An individual reactive power control circuit for individually giving a circulating current command to the circulating current control circuit for individually controlling the circulating current of the cycloconverter. 3. A plurality of loads, each of which is supplied with power from a plurality of circulating current type cycloconverters connected in parallel through a power receiving end of the AC power supply, and a batch insertion collectively connected to the power receiving end of the AC power supply. Phase-advancing capacitors, individual phase-advancing capacitors respectively connected to power supply systems for the plurality of circulating current type cycloconverters, a load current control circuit for controlling the load current of the cycloconverter, and a circulating current of the cycloconverter. Circulating current control circuit, integrated reactive power detector that detects reactive power at the receiving end, individual reactive power detector that detects reactive power generated individually by the cycloconverter, actual reactive detected by the integrated reactive power detection circuit When the power is delayed reactive power, the delayed reactive power does not generate an output in the predetermined dead zone, but outputs when the dead zone is exceeded. A limiter circuit that generates an output according to the advanced reactive power when the advanced reactive power is generated,
A calculation control compensation circuit that generates an individual reactive power command according to the output of this limiter circuit, based on the deviation between the individual reactive power command generated by this calculation control compensation circuit and the reactive power detected by the individual reactive power detector. An individual reactive power control circuit for individually giving a circulating current command to the circulating current control circuit for individually controlling the circulating current of the cycloconverter. 4. A limiter circuit for limiting an upper limit value and / or a lower limit value of a reactive power command output by a control circuit for deriving an individual reactive power command.
4. A parallel operation device for a cycloconverter according to any one of 3 above. 5. The cycloconverter according to claim 1, further comprising a limiter circuit for limiting an upper limit value and / or a lower limit value of the circulating current command output from the individual reactive power control circuit. Parallel operation device. 6. A limiter circuit for limiting the upper limit value and / or the lower limit value of the reactive power command output by the control circuit for deriving the individual reactive power command and the circulating current command output by the individual reactive power control circuit, respectively. Claim 1 characterized by the above.
The parallel operation device of the cycloconverter in any one of Claims 1-3.